Aliev R, Navarro-González R

Language: English
References: 26
Page: 5-11
PDF size: 195.99 Kb.

ABSTRACT

We report here a new approach to study the mechanism of radiation-chemical transformations in polymeric materials based on the combined analysis of radiolytic gases, and pyrolytic products from preirradiated polymers by flash pyrolysis coupled to gas chromatography –Fourier transformed infrared spectroscopy– mass spectrometry with electron impact mode (GC-FTIR-MS). LexanLexan, radiolysis, flash pyrolysis, GC-FTIR-MS, mechanism of degradation. (bisphenol-A polycarbonate) was studied in the dose range from 0.125 to 1.0 MGy. Lexan irradiation was accompanied by the preferential release of carbon monoxide followed by minor production of hydrogen, carbon dioxide and methane. Pyrolyzed Lexan releases mainly carbon dioxide, methane, benzene, toluene, phenol and 4-methyl-phenol. On the basis of these results we suggest two main pathways of Lexan radiation-induced scission with equal probabilities: (a) carbonate bond and (b) aliphatic-aromatic bond ruptures.

REFERENCES

1. Clough, R.L.& Shalaby, S.W. Radiation Effects on Polymers. ACS Symposium Series 475 (American Chemical Society, Washington, 1991).

2. Ivanov, V.S. Radiation Chemistry of Polymers, 123-196 (VSP, Utrecht, 1992).

3. Tabata, Y. CRC Handbook of Radiation Chemistry, 721-750 (CRC Press, Boca Raton, 1991).

4. Woods, R.J. & Pikaev, A.K. Applied Radiation Chemistry: Radiation Processing, 341-391 (John Wiley & Sons, New York, 1994).

5. Bhattacharya, A. Radiation and industrial polymers. Prog. Polym. Sci. 25 (3), 371-401 (2000).

6. Golden, J.H. & Hazell, E.A. Degradation of polycarbonate by ionizing radiation. J. Polym. Sci. A 1 (8), 1671-1686 (1963).

7. Hama, Y. & Shinohara, K. J. Electron spin resonance studies of polycarbonate irradiated by -rays and ultraviolet light. J. Polym. Sci. A-1 8 (3), 651-663 (1970).

8. Ouano, A.C., Johnson, D.E., Dawson, B. & Pederson, L.A. Chain scission efficiency of some polymers in -radiation. J.Polym. Sci., Polym. Chem. Ed. 14 (4), 701-711 (1976).

9. Acierno, D., La Mantia, F.P., Spadaro, G., Titomanlio, G. & Calderaro, E. Effect of radiation conditions on some properties of a polycarbonate. Radiat. Phys. Chem. 17 (1), 31-34 (1981).

10. Kalkar, A.K., Kundagol, S., Chand, S. & Chandra, S. Effect of gamma-irradiation on structural and electrical properties of poly(bisphenol-A carbonate) films. Radiat. Phys. Chem. 39 (5), 435-442 (1992).

11. Shamshad, A., Rashid, M. & Husain, A. High gamma dose dosimetry by polycarbonates. Radiat. Phys. Chem. 50 (3), 307-311 (1997).

12. Araujo, E.S., Khoury, H.J. & Silveira, S.V. Effects of gammairradiation on some properties of durolon polycarbonate. Radiat. Phys. Chem. 53 (1), 79-84 (1998).

13. Navarro-González, R. & Aliev, R. Gaseous products formed by gamma-irradiation of bisphenol-A polycarbonate. Polym. Bull. 45 (4-5), 419-424 (2000).

14. Pu, H., Tang, X. & Xu, X. Studies on polycarbonate/polystyrene/polycarbonate-g-polystyrene blends. Polym. Intern. 43 (1), 33-38 (1997).

15. Aliev, R., García, P. & Burillo, G. Graft polymerization of acrylic acid onto polycarbonate by the preirradiation method. Radiat. Phys. Chem. 58 (3), 299-304 (2000).

16. Aliev, R., Cedillo, G. & Burillo, G. Radiation crosslinking of bisphenol-A polycarbonate in the presence of bisphenol-a dimethacrylate and triallyl cyanurate. Polym. Bull. 45 (2), 167-174 (2000).

17. Ohtani, H. & Tsuge, S. in: Applied Polymer Analysis and Characterization (ed. Mitchell, J.Jr.) 217-232 (Hanser Publishers, Munich, 1987).

18. Hammond, T. & Lehrle, R.S. in: Comprehensive Polymer Science, v.1 (ed. Booth, C. & Price, C.) 589-612 (Pergamon Press, Oxford, 1989).

19. Crompton, T.R. Practical Polymer Analysis, 655 (Plenum Press, New York, 1993).

20. Applied Pyrolysis Handbook (ed.Wampler T.P.) (Marcel Dekker, New York, 1995).

21. Blazsó, M. Recent trends in analytical and applied pyrolysis of polymers. J. Anal. Appl. Pyrolysis 39 (1), 1-25 (1997).

22. Tsuge, S., Okumoto, T., Sugimura, Y. & Takeuchi, T. J. Pyrolys-gas chromatographic investigation of fractioned polycarbonates. Chromatogr. Sci. 7 (2), 253-256 (1969).

23. Ito, Y., Ogasawara, H., Ishida, Y., Ohtani, H. & Tsuge, S. Characterization of end groups in polycarbonates by reactive pyrolysis-gas chromatography. Polym. J. 28 (12), 1090-1095 (1996).

24. Wiley, R.H. Mass spectral characteristics of poly(4,4’- isopropylidenediphenyl carbonate). Macromolecules 4 (2), 254-259 (1971).

25. Foti, S., Giuffrida, M., Maravigna, P. & Montaudo, G. Direct mass spectrometry of polymers. VII. Primary thermal fragmentation processes in polycarbonates. J. Polym. Sci., Polym. Chem. Ed. 21 (6), 1567-1581 (1983).

26. Puglisi, C. & Sturiale, L. Thermal decomposition processes in aromatic polycarbonates investigated by mass spectrometry. Macromolecules 32 (7), 2194-2203 (1999).